Development of Impact Testing Machine and of Non-destractive Characterization Technic for Sintered Tool Materials

烧结刀具材料冲击试验机及无损表征技术的研制

• 批准号: 59850025
• 负责人: USUI Eiji
• 金额: $ 2.94万
• 依托单位: Tokyo Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Developmental Scientific Research
• 财政年份: 1984
• 资助国家: 日本
• 起止时间: 1984 至 1985
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-59850025/
• 关键词: Chipping; Sintered material; impact test

As cutting edge chipping is one of the most troublesome problems in machining practice, it is required to establish the system which enables to predict the chippig. The system eatablished needs two major informations, one is the stress and temperature distributions within cutting edge which are determined by the cutting conditions. The other is the fracture characteristics and thier changes of tool material under practical cutting conditions. This profect proposes the method to obtain the lather informations.In order to obtain the behavior of fracture characteristics and their changes of sintered tool materials under such conditons that are encountered in interrupted cutting operations, both of the impact tension and compression loading testing machine must be specially developed, in which a control of loading rate or a rising time of load and temperature as well as applied stress and cycles are arbitrarily possible.The results obtained by the developed testing machine are sumerized as … More follow: For carbide material P20(1) The carbides, considered as extremely brittle material, are also deteriorated by cyclic loading like a fatigue seen in a ductile material. The fracture stress decreases with increase of impact stress and cycle.(2) The deterioration rate greatly depends on the loading rate. The impact loading gives larger deterioration than the slow one.(3) The threshold stresses are found in both impact tension and compression deterioration stresses.(4) The fracture stress decreases monotonously with temperature rise, however at all temperature less than 800゜C brittle fracture may be seen.(5) Temperature plays no important effect on the deterioration of carbide material. For sintered ceramic <Al_2> <O_3>(6) The ceramic is also deteriorated by repetition of impact stress as same manner that the sintered carbide P20.(7) The fracture stress does not decrease monotonously with temperature rise, but the maximum fracture stress and also the fracture like a ductile manner are seen at about 850゜C.(8) The effect of temperature on deterioration is very large. The fracture stresses decrease extremely and they scatter in very wide range.Finally, non-destructive characterization method of deterioration level is discussed. It is clear that the progress of deterioration gives an increase of attenuation of ultrasonic wave in the material, however at this stage the quantitative relation of the deterioration level and the attenuation can not seen. The reason may be considered that the attenuation in a contact layer between specimen and detector can not be fixed. Less

切削刃崩刃是切削加工实践中最棘手的问题之一，因此需要建立能够预测崩刃的系统。该系统的建立需要两个主要信息，一是由切削条件决定的切削刃内部的应力和温度分布。二是刀具材料在实际切削条件下的断裂特征及其变化。本课题提出了获得泡沫信息的方法，为了获得烧结刀具材料在断续切削条件下的断裂特性及其变化，必须专门研制冲击拉伸和压缩载荷试验机，该试验机可任意控制加载速率或载荷和温度的上升时间以及施加的应力和循环次数。 ...更多信息 随后：对于碳化物材料P20（1）碳化物被认为是极脆的材料，也会因循环载荷而劣化，如韧性材料中所见的疲劳。断裂应力随冲击应力和循环次数的增加而降低。(2)劣化率在很大程度上取决于加载速率。冲击加载比慢速加载的劣化程度更大。(3)在冲击拉伸和压缩两种破坏应力中都存在临界应力。(4)断裂应力随温度的升高而单调降低，但在低于800 ℃的所有温度下都可以看到脆性断裂。(5)温度对硬质合金材料的劣化影响不大。对于烧结陶瓷<Al_2><O_3>（6），与烧结碳化物P20相同，陶瓷也因反复冲击应力而劣化。(7)断裂应力并不随温度的升高而单调下降，但在850 ℃左右出现最大断裂应力，且断裂呈韧性断裂。(8)温度对变质的影响很大。最后，讨论了劣化程度的无损表征方法。很明显，劣化的进展使超声波在材料中的衰减增加，然而在这个阶段，劣化水平和衰减的定量关系是不可见的。其原因可以认为是试样与探测器之间的接触层中的衰减不能被固定。少

项目成果

JSPE preprint. (1985)

JSPE 预印本。

JSPE preprint. 133. (1983)

JSPE 预印本。

Journal of J.S.P.E.48-10. (1932)

J.S.P.E.48-10 杂志。

JSPE preprint. 744. (1985)

JSPE 预印本。

精機学会春季大会講演論文集. 744. (1985)

日本精密机械学会春季会议论文集 744。（1985）